This invention relates to slide calculators and images, in various shades, of various colors including neutral and white, and more specifically, to a calculator for determining the correct flash-to-background distance for creating color (includes shades of gray and white) backgrounds for photography using color filters (or no filter) over the flash lens and a neutral gray background and without the necessity of an electronic light meter. Some of the factors affecting the amount and quality of light striking the film in a camera are lens f-stop, exposure factors of filters over the camera lens, exposure factors of filters over the flash lens, size of the flashes, the distance of the main-light from the subject, the distance of the subject from the background, and the distance of the background-flash from the background.
The most common method used to produce a colored background (or neutral or white) in studio photography is to use a seamless roll of background paper of the desired color made specifically for this purpose. This requires the photographer to purchase a roll for every color that he may wish to use. Each roll costs about $35.00. The photographer sets up his lights and takes a meter reading and continues adjusting the lights and taking meter readings until he thinks the distance is correct. When using flash, an expensive electronic flash meter is required.
A different attempt is to put a color filter over the background light and project this color onto the background. The problems with this is that, until this invention, there was not a definite method to follow which would give predictable results. When using flash, it is impossible to visually inspect the amount of light on the background and adjust it until it is satisfactory. This invention provides a means for visually selecting a color and shade and determining exactly the distance required for the background-flash to reproduce that color and shade.
Prior to this invention, some of the unpredictable variables were
(a) the background used may have had some color already inherent in it which would affect the color balance of the photograph.
(b) the density of the background may not have been known.
(c) without an electronic flash meter, the correct distance for the background-flash could only be guessed at.
(d) it was possible to visually select a color and shade and reproduce it even with the use of an electronic flash meter.
One or more of the following basic assumptions are made in almost every book or article on lighting color backgrounds:
(a) the photographer owns a balanced set of quartz lights;
(b) the photographer owns a balanced set of flashes with modeling lights that are proportional to the strobes;
(c) the photographer owns an electric flash meter if he is using flash;
(d) the photographer owns several rolls of seamless background paper of different colors;
(e) the studio is large enough to accommodate professional equipment;
(f) the photographer is willing to spend his time, the model's time and film required to find the background color and intensity he wants through trial and error.
None of the above are required when using this invention to produce color backgrounds with non-professional electronic flash.
Kodak publishes a book titled "Professional Portrait techniques" in which the instructions on lighting colored backgrounds consists of two paragraphs:
"Background Lighting: For the photograph to retain the same background color as you observe visually, the background must receive the same amount of illumination as the subject's face. For example, if the main light is 4 feet from the face, a light of equal intensity must be placed 4 feet from, and turned toward, the background. Position the subject 5 or 6 feet from the background in order to reduce the tendency for the spill from the main light to affect the background tone and color saturation. Do not rely on spill light to illuminate the background; it should be treated as a separate subject. Light it independently.
"Two other excellent reasons for placing the subject at least 5 or 6 feet from the background are to prevent the background color from reflecting appreciably onto the subject and to allow background detail to go out of focus."
Notice that Kodak expects the photographer to have a background light equal to his main light. Kodak does not attempt to explain how to use color filters with flash to create color backgrounds. A search of 16 other books on photographic lighting revealed no information on how to reproduce a specific color and shade desired using color filters on a flash. The books are
Set Up Your Home Studio, (Kodak Limited), 1985
Gowland's Guide to Glamour Photography, Peter Gowland, 1972
The Secrets of Photographing Women, Peter Gowland, 1981
Photographic Lighting, Ralph Hattersley, 1979
Pro Techniques of People Photography, Gary Bernstein, 1984
Figure Photography, David Brooks, (Petersen's Photographic Library), 1974
Nude Photography, Peter Lacey, 1985
Portrait Photography How and Why, Mary Allen, 1977
Light and Lighting in Photography, Andreas Feininger, 1976
Exposure Control and Lighting, J. D. Cooper and J. C. Abbot, (Nikon Series), 1979
Special Effects Photography, Kathryn Livingston, 1985
How to Control & Use Photographic Lighting, David Brooks, 1980
How to Use Light Creativity, (HP Books), 1981
Electronic Flash, Jim Cornfield, (Petersen's Photographic Library), 1980
50 Portrait Lighting Techniques For Pictures That Sell, John Hart, 1983
The Art of Portraits and the Nude, (Kodak), 1983
Therefore, there is still a need for a calculator and companion images of shades of color, neutral and white, with matching filters, making it possible to calculate accurate flash working distances for a variety of colored, neutral or white backgrounds without the necessity of changing rolls of background paper each time a color change is needed, and without the need for the background-light and main-light to be equal or the need for an expensive electronic flash meter.
It is the object of this invention to make available to photographers, at a modest cost, an easy, accurate method of determining the necessary distance between the background-flash and the background which will reproduce a background color and shade, which is visually selected from images of a gray scale illuminated with color filters and no filter and identified as such--this taking into consideration many variables, some of which are:
(a) lens aperture (f-stop)
(b) film speed (ISO rating)
(c) density of filters (Filter Exposure Factor)
(d) relative power of flash (Guide Number or GN)
(e) the relative darkness (shade) of the Gray Background
These and other objects of the invention will become apparent from the following description and appended claims.